Absorption refrigerator



June 15, 1954 K. G. BOREN ETAL 3,137,147

ABSORPTION REFRIGERATOR Filed Jan. 27, 1961 3 Sheets-Sheet 2 FIG. 2

j 37 2% 45 w INV TORS I I Q I WWW/W A KW June 1964 K. G. BOREN ETAL ABSORPTION REFRIGERATOR 3 Sheets-Sheet 3 Filed Jan. 27, 1961 A A mm:

(M my g olzs BY 1 kWh/MA 4* M! a 7 an inert gas or, pressure equalizing agent.

3,137,147 ABSGRPTIGN REFRIGERATOR Karl Gunnar Boren, Vallingby, and Paul Herbert Cronelid, Stockholm, Sweden, assignors to Airfieholaget Eiectrolux, Stockholm, Sweden, a corpora-v tion of Sweden Filed Jan. 27, 1961, Ser. No. 85,419 Claims priority, application Sweden Jan. 30, 1960 3 Claims. (Ci. 62-454) 7 cabinet of this type an absorption refrigeration apparatus of U-shape in which at least one component is disposed in an insulated wall of the cabinet and forms the closed end of the U, the cooling element is disposed in the thermally insulated storage space and forms one arm of the U, and other components are disposed exteriorly of the storage space and form the other arm of the U.

A' further object is to provide for a portable absorption United States Patent into liquid absorbent, such as Water, which enters through a conduit 28. Inert gas weak in refrigerant is returned to the lower end of cooling element 17 from the upper end of absorber coil 27 in a path of flow including the inner passage of gas heat exchanger 24. Absorption liq uid enriched in refrigerant in the absorber 27 passes into] the absorber vessel 26 and flows therefrom through a conduit 29 to generator 19 where it is heated and refrigerant refrigerator a cabinet in which the closed end of absorpplace by the insulation of insulated wall structure of the v cabinet.

A still further object is to anchor and firmly hold in place the closed end of absorption refrigeration apparatus of U-shape in the insulated walls of a cabinet by a body of rigid foamed plastic which is formed in situ and possesses significant mechanical strength.

The novel features we believe to be characteristic of our invention are set forth with particularity in the claims. The invention, both as to organization and method, together with the above and other objects and advantages thereof, will be better understood by reference to the following description taken in connection with the accompartying drawings forminga part ofthis specification, and in'which:

. FIG. 1 is a vertical sectional view, taken at line 1--1 FIGS. 4 and 5 are fragmentary vertical sectional views taken at lines 44 and 55, respectively, of FIG. 3.

Referring to FIG. 1, the invention .is shown in connec- 7 tion with a portable refrigerator of small size which comprises a cabinet 10 having a one-piece inner metal shell or liner 11 arranged to be supported within an outer metal insulated closure or lid 16. The storage space 14 is arranged to be cooled by a cooling element or evaporator 17 which is disposed therein. I

The cooling element 17 desirably forms a part of refrigeration apparatus 18 of an absorption type containing In such apparatus, refrigerant vapor expelled from solution in a generator 19 by heating flows through a conduit20 to a condenser 21 in which it is liquefied. The liquid refrigerant,

vapor again is expelled out of solution. The weakened absorption liquid from which refrigerant hasbeen expelled as vapor is conducted from the generator 19 to the absorber 27 through the conduit 28 to again absorb re 'frigerant vapor. V i

In order to simplify the drawings, parts of the refrigeration apparatus have been omitted and other parts have been shown only diagrammatically, a complete illustration of the apparatus not'being'necessary for an understanding of our invention. The parts of refrigeration apparatus of the absorption type, whose relative positions are substantially fixed, usually are formed of iron or steel when ammonia and Water are employed as' the refrigerant and liquid absorbent, respectively. Therefore, the piping for the cooling element 17, which is connected by,the gas heat i exchanger 24 and conduits to other parts of'the refrigera-" tion apparatus and forms a unitary part thereof, may be formed of such ferrousmetal.

The refrigerator cabinet 10 is of rectangular shape having long front and rear insulated walls 30 and 31, respectively, and shorter connecting end insulated walls 32 and 33. The outer shell 12c'omprises front and rear walls 34 and 35, lateral end walls 36 and 37, and top and bottom walls 38 and 39. A base 40 having feet 41 is fixed to the bottom of cabinet 10. A plate 42 forms the outside panel of the rear insulated wall 31 of the cabinet, as shown in FIG. 1. The lateral end walls36 and 37 extend rearwardly beyond the plate 42 to provide a vertical "compartment 43 in which parts of the refrigeration apparatus.

40 and passing through openings 3811 at the rear part of the top 38 of the cabinet. 7 v

The portable refrigerator illustrated in the-drawing and described above being of relatively small size may be carried in the trunk compartment of an automobile, for example; The refrigerator may be provided with handles 45 at the end walls 36 and 37, as shown in FIG. 2, or-it may be carried with the aid of straps (not shown) fastened to the handles 45 or to the outer shell 12. As "seen in FIG. 1, the generator'19 is adapted for'electrical and gas operation. Accordingly, the generator 19 may be pro'videdwith an electrical heating element (not shown) having conductors 46 and47 extending exteriorly of the generator which are adapted to be connected to a source of electrical supply, as to the storage battery of an auto-;

from the bottom of the generator and is arranged to be heated by a gas burner 49. Small containers of comi pressed combustible gas, such as liquid propane, for example, which are either refillable or of the throw-away type, may be employed as the source of gaseous fuel for operating the refrigerator with gas when camping or picnicking, for example, and a source of electrical supply is not available. The upper end of the heating flue 48 projects upward from the top of the generator 19 and is in communication with a flue extension pipe or air dilution flue 50 which projects upward in the apparatus compartment 43 with its upper end passing through the top wall 38 of the cabinet and substantially flush therewith.

In accordance with this invention, in order to provide a portable heat-operated refrigerator of the absorption type having a storage space 14 of maximum volume for a narrow elongated cabinet 10 of a given size, the absorption refrigeration apparatus is of U-shape having the cooling element 17 and parts in apparatus compartment 43, respectively, forming the spaced arms of the U and the gas heat exchanger 24 forming the closed end of the U.

The apparatus compartment 43 extends lengthwise of the narrow elongated cabinet 10 between the plate 42 and rear wall 35, as shown in FIGS. 1 and 2. The generator 19 is positioned at the corner of the apparatus compartment 43 defined by the rear wall 35 and end wall 36. The absorber coil 27 extends lengthwise of the compartment 43 between the generator 19 and end wall 37, while the condenser 21 extends lengthwise of the apparatus between the end walls 36 and 37. Accordingly, the generator 19, absorber vessel 26, absorber coil 27 and condenser 21 form one arm of the U-shaped refrigeration apparatus which is disposed in the narrow elongated apparatus compartment 43 at one side of the thermally insulated storage space 14.

The gas heat exchanger 24 forms the closed end of the U-shaped refrigeration apparatus and is disposed in the thermally insulated end wall 33, as shown in FIGS. 2 and 3, Further, the conduit 22 for conducting condensed refrigerant from condenser 21 to cooling element 17 includes a first section 22a heat conductively connected at 51 to the gas heat exchanger 24 and a second section 22b heat conductively connected at 52 to the cooling element 17. In this way the temperature of condensed refrigerant, in its path of flow from condenser 21 to cooling element 17, is effectively lowered.

The cooling element 17, which extends lengthwise of the cabinet 10 along the front wall 34 between the end walls 36 and 37, comprises a looped coil in which all parts thereof are disposed in a single vertical plane substantially parallel to the front insulated wall 30 and closely adjacent thereto. The looped coil includes spaced horizontal legs 17a and 17b and a connecting bend 17c at the vicinity of the end insulated wall 32. The section 22b of the condensate conduit 22 is formed with a U-bend with parts thereof thermally connected at 52 to the upper and lower legs 17a and 17b of the cooling element 17.

By locating the cooling element 17 in the upper part of storage space 14 and closely adjacent to the thermally insulated wall 30 so as to provide a relatively narrow passage'53, the natural circulation of air, which is induced by air coming in contact with the looped coil, is promoted. A vertically extending plate 54 is fixed to the side of cooling element 17 removed from the front insulated wall 30. As shown in FIGS. 4 and 5, the top and bottom edges 54a. and 54b of plate 54 are of arcuate shape and tightly fit about the upper and lower horizontal legs 17a and 171), so that there will be a good heat conductive connection between the plate 54 and the cooling element. The thermal bond between the plate 54 and coil 17 may be improved in any suitable manner, as by dipping these parts in a body of molten zinc, for example. The plate 54 not only increases the heat transfer surface of the cooling element 17 but also provides a vertical wall member which further promotes natural circulation of air in the storage space 14. I

The plate 54 is provided with a pair of spaced tabs 55 and 56 which may be formed by bending parts of the plate, thus forming an opening 57 in the plate. The bottom tab 56 is formed in such manner that small lugs 53 project upward from the bottom tab 56 at one longitudinal edge thereof. The tabs 55 and 56 are in good physical contact with the legs 17a and 17b, respectively, the bottom tab 56 serving as a small shelf upon which an ice tray can be placed for freezing water and other matter. The lugs 58 serve as stops to'prevent an ice tray from slipping and falling from one edge of tab 56, While the portion of inner shell 11 at the vicinity of the tab 56 prevents the tray from falling from the opposite edge of the tab.

In accordance with this invention, the refrigeration apparatus is firmly anchored in the cabinet by insulation 60 formed in situ in the thermally insulated walls 30, 31, 32 and 33. The insulating material preferably is foamed plastic of a type that adheres very strongly to the parts of the refrigeration apparatus and to the surfaces defining the insulating spaces. Foamed insulation of this kind completely fills the insulating spaces to provide an insulation 60 that is extremely etficient and is self-sustaining and possesses significant mechanical strength, whereby a portable refrigerator of small size is provided that is extremely rigid and utilizes theinsulation to support and hold the inner liner 11 in position within the outer shell 12. Therefore, the insulation 60 may be formed in situ in the walls 30, 31, 32 and 33 by employing a foam plastic like polyurethane, for example, to which dichlorodifluorrnethane, for example, has been added which liberates a heavy gas in the resulting foamed insulation.

In order to form the insulation 60 in situ in the refrigerator of FIGS. 1 to 5, the inner shell 11 is provided with an oblong opening 61, as shown in FIG. 3, through which the cooling element 17 may be inserted to position it within the storage space 14. The opening 61 may then be closed in any suitable manner, as by a plate 62, as shown in FIG. 3, which is fixed to the inner shell 11. The outer casing 12 is next positioned over the inner shell 11 and refrigeration apparatus, the partition 42 having a vertically extending slit .63 at the vicinity of gas heat exchanger 24 which extends upward from its bottom edge to the height of condensate conduit section 22a. Thereafter, the slit 63 is closed by a plate 64 fixed to the plate 42.

The inner shell 11 is formed with an outwardly extending flange 65 about the top opening 15 of the storage space 14. The top 38, which may be formed of material having poor heat conductivity, such as plastic, for example, is provided with downward extending flanges 66 which overlap the outer enlarged peripheral edge portions 65a of the flanges 65 to close the insulation spaces atthe top of the cabinet. Suitable sealing material (not shown) may be employed at the undersides of the flanges 65 to seal the joints between them and the flanges 66.

With the parts in an inverted position from that shown in FIG..-1 and the lower ends of the insulation spaces open, the inner shell 11 and refrigeration apparatus are accurately located and positioned within the outer shell 12 after which the foamable plastic material, such as polyurethane plastic, and a substance like dichlorodifiuoromethane, is introduced. The resulting foamed plastic completely fills the spaces between the inner liner 11 and outer walls 34, 36 and 37 and plate 42 to form the insulated walls 30 to 33 at the front, lateral end walls and plate 42 of the cabinet 10. When foaming of the plastic is taking place, the hollow wall spaces become completely filled with the insulating material. Before the foaming has terminated and the foamed plastic has set and hardened, the bottom plate 39 is fixed to the bottom of the cabinet 10.

It will now be understood that an improved refrigerator has been provided in which a foamed plastic insulation can be formed in situ for effectively insulating the walls of the storage space 14. Not only does the insulation 60 effectively anchor the U-shaped refrigeration apparatus at the closed end of the U, but the insulation also effectively insulates the gas heat exchanger 24 which, of

necessity, must be insulated in any event to insure efficient operation of the refrigeration apparatus. Further, the anchoring of the gas heat exchanger 24 in the insulated wall 33 provides a rigid and sturdy construction, whereby the refrigerator is less sensitive to vibration and jarring which may be encountered when the refrigerator is being transported from place to place. This is so because the insulated walls-30, 31, 32 and 33 form a thermally insulated storage space of maximum volume is obtained for a cabinet of a given size. This arrangement provides a portable refrigerator which can be conveniently carried like a piece of hand luggage on camp- .ing trips or picnics, for example.

Modifications of the embodiment of our invention which has been described will occur to those skilled in the art. Therefore, as we desire our invention not to be limited to the particular arrangement set forth, we intend in the claims to cover all those modifications which do not depart from the spirit and scope of the invention. We claim: t 1. A portable refrigerator adapted to be carried like a piece of hand luggage which comprises a rectangular cabinet including thermally insulated wall structure de-.

fining a storage space having an access opening and a closure member therefor, said thermally insulated wall structure including a bottom wall and an upstanding side wall and a body'of foamed plastic comprising a first part in the bottom'wall which is of rectangular form and a second integral part in the upstanding side wall 7 which is of annular form having four sides, hermetically sealed absorption refrigeration apparatus of the pressure-equalized type containing refrigerant, inert gas and absorption liquid, the apparatus comprising a plurality of parts which are united to one another and are relatively immovable with respect to one another and include a cooling element, a gas heat exchanger and heat dis- 1 sipating components comprising a condenser and an absorber, the cooling element being disposed in the storage space and the heat dissipating components being disposed in a vertical plane outside of the thermally insulated wall structure, the gas heat exchanger being embedded in one of the sides of the foamed plastic body which is selfsustaining and possesses significant mechanical strength, and means comprising the body of foamed plastic for supporting the refrigeration apparatus on the cabinet, the coolingelement and heat dissipating components being substantially parallel to the two sides of the foamed plastic body perpendicular to the one side and extending toward the opposite side thereof.

2. Apparatus as set forth in claim 1 in which the walls of the thermally insulated wall structure comprise spaced outer and inner wall rnembers defining spaces for the first and second parts of the body of foamed plastie, the body of foamed plastic being bonded to the inner faces of the outer and inner wall members and to the exterior surface of the gas heat exchanger.

3 Apparatus as set forth in claim 1 in which the access opening is provided by a top opening of the storage space and the rectangular cabinet includes first and second parallel exterior side wall members and third and fourth parallel exterior end wall members which connect the first and second exterior side wall members and are perpendicular thereto, a plate which is parallel to the first and second exterior side wall members and disposed therebetween, the plate and second exterior side wall member defining a'compartment outside of and alongside References Cited in the file of this patent UNITED STATES PATENTS 2,177,880 ,Schellens et al Oct. 31, 1939 2,653,139 Sterling Sept. 22, 1953 2,794,331

Kogel u June 4, 1957 

1. A PORTABLE REFRIGERATOR ADAPTED TO BE CARRIED LIKE A PIECE OF HAND LUGGAGE WHICH COMPRISES A RECTANGULAR CABINET INCLUDING THERMALLY INSULATED WALL STRUCTURE DEFINING A STORAGE SPACE HAVING AN ACCESS OPENING AND A CLOSURE MEMBER THEREFOR, SAID THERMALLY INSULATED WALL STRUCTURE INCLUDING A BOTTOM WALL AND AN UPSTANDING SIDE WALL AND A BODY OF FOAMED PLATIC COMPRISING A FIRST PART IN THE BOTTOM WALL WHICH IS OF RECCTANGULAR FORM AND A SECOND INTEGRAL PART IN THE UPSTANDING SIDE WALL WHICH IS OF ANNULAR FORM HAVING FOUR SIDES, HERMETICALLY SEALED ABSORPTION REFRIGERATION APPARATUS OF THE PRESSURE-EQUALIZED TUPE CONTAINING REFRIGERANT, INERT GAS AND ABSORPTION LIQUID, THE APPARATUS COMPRISING A PLURALITY OF PARTS WHICH ARE UNITED TO ONE ANOTHER AND ARE RELATIVELY IMMOVABLE WITH RESPECT TO ONE ANOTHER AND INCLUDE A COOLING ELEMENT, A GAS HEAT EXCHANGER AND HEAT DISSIPATING COMPONENTS COMPRISING A CONDENSER AND AN ABSORBER, THE COOLING ELEMENT BEING DISPOSED IN THE STORAGE SPACE AND THE HEAT DISSIPATING COMPONENTS BEING DISPOSED IN A VERTICAL PLANE OUTSIDE OF THE THERMALLY INSULATED WALL STRUCTURE, THE GAS HEAT EXCHANGER BEING EMBEDDED IN ONE OF THE SIDES OF THE FOAMED PLASTIC BODY WHICH IS SELFSUSTAINING AND POSSESSES SIGNIFICANT MECHANICAL STRENGTH, AND MEANS COMPRISING THE BODY OF FOAMED PLASTIC FOR SUPPORTING THE REFRIGERATION APPARATUS ON THE CABINET, THE COOLING ELEMENT AND HEAT DISSIPATING COMPONENTS BEING SUBSTANTIALLY PARALLEL TO THE TWO SIDES OF THE FOAMED PLASTIC BODY PERPENDICULAR TO THE NE SIDE AND EXTENDING TOWARD THE OPPOSITE SIDE THEREOF. 